Preheat oven to 200 degrees. Trace an 8-inch circle onto a piece of parchment paper. Turn over paper and place on a baking sheet. In a food processor, puree half the raspberries, 1 teaspoon sugar, and lemon juice until smooth. With a rubber spatula, press mixture through a fine-mesh sieve into a medium bowl. Discard solids and set sauce aside. In a small bowl, whisk together 3/4 cup sugar and cornstarch.

STEP 2

In a large bowl, using an electric mixer, beat cream of tartar, egg whites, and pinch of salt on high until foamy. Reduce speed to low and add sugar mixture in 3 additions, beating on high 30 seconds after each addition. Scrape down bowl and beat on high until stiff peaks form, 3 to 4 minutes.

STEP 3

Add 2 tablespoons raspberry sauce to meringue, but do not stir. With rubber spatula, mound meringue (it will ripple as you scoop) onto prepared parchment on sheet, using circle as a guide.

STEP 4

Bake meringue until crisp and dry on outside, about 1 hour 50 minutes. Turn off heat and let meringue dry in oven, 1 hour. Remove from oven and let cool completely on sheet on a wire rack. To serve, gently peel meringue from parchment and transfer to a platter. Top with whipped cream and remaining raspberry sauce and raspberries.